Fabriken



UNITED STATES PATENT OFFICE.

ROBERT E. SCHMIDT, OF ELBERFELD, GERMANY, ASSIGNOR TO THE FARBEN- FABRIKEN, VORMALS FR. BAYER & 00., OF SAME PLACE.

ALlZARlNE DERIVATIVE.

SPECIFICATION forming part of Letters Patent No. 476,418, dated June 7, 1892.

Application filed November 18, 1891. Serial No. 412,302. ($pecimens.)

To all whom it may concern: water and theliquid is heated for a short time Be it known that 1, ROBERT E. SCHMIDT, to boiling. The separated dye-stuff maythen doctor of philosophy, chemist, (assignor to the be filtered olt, and after having been purified FARBENFABRIKEN, VORMALS FR. BAYER 8: from the adhering sulphuric acid by washing o 5 00., at Elberfeld,) a subjectof the Emperor with water it may directly be employed for of Germany, residing at Elberfeld, Germany, dyeing. My new product thus obtainedforms have invented a new and useful Improvement a greenish-black amorphous mass with mein the Manufacture of Alizarine Derivatives, tallic luster. It is almost insoluble in cold of whichI givein the followingaspecification. and hot water, soluble in sodium carbonate 10 My invention relates to the production of a with reddish-blue color, and very easily in new alizarine compound by oxidizing the soda-lye with greenish-blue color, and in amalizarine bordeaux of my Letters Patent No. monia with pure blue color. It is dissolved 4%,893, dated February 24, 1891, in sulphuricby concentrated sulphuric acid with pure acid solution at a low temperature with not greenish-blue color, out of which solution yel- 6o 1 5 too great an excess of manganese and by comlowish-brown flakes are precipitated on the bining the resulting oxidized product with addition of water. It dyes wool mordanted salicylic acid, likewise in sulphuric-acid sowith chromium salts in greenish-blue shades. lution. Having thus described my invention, what In carrying out my process practically I pro- I claim as new, and desire to secure by Letters 2o ceed as follows: Ten kilos of dried alizarine Patent, is

bordeaux are dissolved in two hundred kilos l. The process for the manufacture of a of sulphuric acid at 66 Baum. Ten kilos of coloring-matter by oxidizing the alizarine borfinely-powdered manganese, containing about. deaux herein described with manganese in eighty-eight per cent. of binoxide, are intro concentrated sulphuric-acid solution and by 70 25 duced into this solution, with the precaution combining the resulting diquinone with salithat the temperature does not surpass 25 oylicacid, likewise in sulphuric-acid solution. centigrade. In this manner a sulphuric-acid 2. The coloring-matter derived from alizasolution results which contains the quinone of rine bordeaumwhich is a greenish-blackamoran oxyanthraquinone, and the reaction that phous mass withmetalliclustenalmost insolu- 0 here takes place is the following: The alizable in cold and hot water, soluble in sodium rine bordeaux, which I have found isa tetracarbonate with reddish-blue color and very oxyanthraquinone, is changed by the action soluble in soda-lye with greenish-blue, and in ofmanganese in sulphuric-acid solution at ammonia with pure blue color,in concentrated first into pentaoxyanthraquinone, and thelatsulphuric acid with greenish-blue color, from 35 ter, which represents an anthraquinone, in which solution yellowish-brown flakes are prewhich five hydrogen atoms are substituted cipitated on the addition of water, and which by hydroxyl, is further oxidized to a diquidyes wool mordanted with chromium salts in none. The said sulphuric-acid solution of greenish blue shades. the diquinone is slowly, and at atemperature In testimony whereof I have signed my 0 not exceeding 25 centigrade, mixed on stirname in the presence of two subscribing witring with ten kilos of salicylic acid. The nesses. combination of the latter acid with the an- ROBERT E SCHMIDT. thradlquinone 1s unlshed when the color of the solution has changed from blue to bluish Witnesses: 4 5 green. After about eighteen hours the whole RUDOLPH FRIOKE,

mass is poured into two thousand liters of IVM. EssENWEIN. 

